Field of the Invention
The present invention relates to an active earphone authentication method, and more specifically, to an active earphone authentication method for distinguishing an active earphone to which an Active Noise Cancelling (ANC) technique is applied by supplying voltage to the earphone by a terminal equipment from a general earphone to which the Active Noise Cancelling (ANC) technique is not applied.
Background of the Related Art
Since a user increases volume when background noises are severe, such an earphone device may act as a factor generating hearing impairment when the user listens to music or broadcast for an extended period of time. Active noise cancelling techniques (ANC) are introduced recently to improve quality of sound of the earphone device. The active noise cancelling technique (ANC) is a technique of analyzing frequencies, magnitudes, sound qualities and the like of various kinds of sounds flowing into the earphone device and offsetting noises by sending out sound waves of reverse wavelength through a speaker. Such an active noise cancelling technique (ANC) is stated in the ‘Active Noise Cancelling System’ disclosed in Korean Patent Publication No. 10-2011-0097622.
However, if the earphone device is changed to an earphone mode to which the Active Noise Cancelling (ANC) technique is not applied while power is supplied to the earphone device and a key button is pressed at the earphone device, excessive current flows through the earphone device.